Manufacture of heat evolving cartridges



June 27, 1933. MELLGREN 1,915,898 I MANUFACTURE OF HEAT EVOLVING CARTRIDGES Filed Dec. 5. 1930 1s j 19 46\ A /11 INVENTOR: 72. 7/72/5 re n ATTORNEYS.-

the central plunger moves.

.nw r n as said P Patented June 27, 1933 PATENT 1 mm I I N118 mans, O! GO TTENBOBG, SWEDEN mono-man or BEAT EVOLVING chart-mans Application and December a, 1930. Serial at. 490,821.

. In the S. Patents Nos. 1417,07 5 and 1,498,323 there are described heating cartridges composed of an alumino heat evolvmg mixture enclosed within a casing which 5 according to the last mentioned patent preferably consists in sheet aluminium. According to the first mentioned patent the mixture is compressed leaving a cavity therein to recame an igniting mixture.

The ob ect of this invention is a method in the manufacture of heating cartridges qt the class mentioned which will improve the.

igniting properties of said cartridges.-

When. manufacturing the cartridge the heat evolving mixture will be compressed within its casing by means of a stamp com= prising two reciprocating parts, viz. one c lindric central plun er and one annular p u'nger with a centre bore through which Of said two plungers the central one at first will be low ered down into the empty cartridge casing, whereby its throw is 0 such a len h, that the plunger stops at some distance a ve the 35 bottom of the cartrid e casing and remains for some moment-in t is position forming a 3 core for the heat evolving mixture'in pow shape which now is poured into the cartridge casing. On account of the core forming cenlw tral plunger a certain pnortion of the casing will not be filled up w the powdered mixture, said ortion corresponding to the cavity intended or the priming composition. The next operation will be that the annular 1w plunger descends againstthe mixture in the casingand com resses same sufiiciently. Be cause of the st' downwards position of the core forming central plunger. that portion of the mixture within the cartridge casing; which lies below the central plunger will be.

On the table 9 there is a mould 11 for the withdrawn from the heavy pressure of the annular plunger, thus leavin said portion of mixture ina somewhat so r consistence than is the main body of the same mixture inthe casing. t i

Now the annular plunger will be raised, unger has-released the pressure upon the mixture inthe cartridge for elevation view of the cartridge when ready to receive the primmg mixture.

casin the central plunger also wind; remove leaving the cavity inthgcartri the priming composition to be supplied therein.

Experience has shown that the softness of the cartridge mixture below the cavity for the priming composition is of im ortancefor the easy ignition of the cartri ge, "as also that the wanted degree of softness can be obtained only if the two reciprocatin plun ers have a s ecial design such as descri d be ow with re erence to the annexed drawing. In 60 said drawing an embodiment of the main parts of the compressing machine is shown dia rammaticall ig. 1 is a sectional elevation view of the machine with a cartridge under 0 eration,

Fig. 2 shows a plan view of a gui ewheel, Fi 3 is a similar view of another guide whee and I Fig. 4 is on an enlarged scale a sectional In the drawing 1 designates the stanchions of the compressing machine, and 2 a shaft carried in bearings 3 on the top of the stanchions and receiving rotation from some power source by means of a belt pulley 4. The shaft 2 is provided with two wheels 5 and 6 stationarily secured to the shaft and provided each with a curved notch 7 and 8 respectively the notch 7 in the wheel 5 curved in another way than the notch 8 in the wheel 6 as a can be seen in Figs. 2 and 3 in which figures the two wheels are seen from those sides which are in front of each other in the machine as per Figure 1, and the wheels disposed in the same mutual relation as in the machine as it concerns the curvatures of their notches.

A table 9 connects the tworstanchions 1, as also somewhat above said table a guide 10. y

cartridge which is to be manufactured, into which mould the metal casing 12 for said cartridgeis supzplied.

of wheel 5 moves the head 13 5 ing 12. In notch 8 of wheel 6 a similar head 17 of a; rod 18 is movable, the thicker lower part 19 of said rod passes through the central bore in the sleeve 16 as also in the annular plunger 16 and thus constitutes a central plunger, surroundedby the annular plunger 16.

When revolving the shaft-2 the notches 7 I and 8 will cause the rods 14 and 18 with their plungers 16 and 19 to reciprocate in such mutual strokes that at first lu er. 19 descends into the casing 12 on t e ta 1e 9, and, having reached its downmost position as exemplified in Fig. 1 leaving some distance free above the bottom of cartridge casing 12, the annular plunger- 16 descends until its downmost position, shown in the same figure. When continuing its revolving, shaft 2 by means of the notches 7 and 8 in the wheels 5 .and 6 respectively raises at first the annular an enlar ed scale in Fi 4. From this fi re g g by it is visi le that the'oentral cavity 20 1c the withdrawn. central plunger 19 is of a conical appearance. r That depends on the fact that the operative end- 22 of the central plunger 19 is bevelled. The reason for said bevelled shape of the plunger is to get that portion 23 of the mixture which is positioned below the cavity 20 less compressed than the main body 24 of said mixture, for the purpose to have the cartridge more easy to ignite when firing the priming composition which is to be supplied into the cavity 20 before the cartridge isready for use.

Should the central plunger 19 be cylindric the pressure upon the main body of the mixture 24 from the annular plunger 16 will cause substantially the same pressure to be transmitted to the central portion 23 also, and the intended object would not be attained. But as the central plunger end 22 is bevelled the pressure from the annular plunger 16 is removed off .from the central portion 23, as is demonstrated by the dot-and-dash lines 25 in Fig. 4 which indicate the boundaries of a cylindrical portion of the mixture 24 which will be somewhat released from the rsssure from plunger 16, whilst the crosswise scattered ortion below the cavity 20 indicates the so compressed central portion 23.

When the priming com osition has been supplied into cavit 20 a li 26'shown by dot- 2. An apparatus for the manufacture of heat evolving cartridges having a central cavity for a priming composition, comprising two reciprocable plungers, one of said plungers av' a substantially conical end surface adapte to form the central cavity for the priming composition in the active mixture of a cartridge, the other plunger having a central bore slidably receiving the first mentioned plunger and-surrounding the latter, at its working end to compress the main body of the active mixture around said cavity, and means for operat' said plungers whereby the first mentioned plunger following the formationof the central cavity in the active material acts to prevent further compression of the active material underlying said cavity during the compression of the main body of the active material by the second mentioned plunger. Y

3. A method of manufacturing heat evolv ing cartridges having metal casings by means .of movable plungers, consisting in advancing one plunger into the metal casing to a point .a. distance above the bottom of said casing,

introducing the powdered active mixture into said casing, advancing the other plunger to compress-the active mixture surrounding the first mentioned plunger whereby the portion of the active mixture underlying the cavity formed by the first mentioned plunger remains soft as compared with the main body of the mixture surroundin said cavity. 4 In testimony whereof, have aflixed my signature.

NILS' MELLGREN. 

